Spinal implant system and method

ABSTRACT

A method for treating a spine is provided. The method includes the steps of: disposing an interbody implant adjacent a posterior portion of an intervertebral disc space; connecting a surgical instrument with at least one fixation element fastened with tissue adjacent the posterior portion; and manipulating the surgical instrument such that tissue adjacent the posterior portion engages the interbody implant and one or more vertebra rotate about the interbody implant. Spinal implants, surgical instruments and systems are disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefits of U.S. Provisional PatentApplication No. 62/105,579 filed Jan. 20, 2015, the contents of whichbeing hereby incorporated in its entirety by reference.

TECHNICAL FIELD

The present disclosure generally relates to medical devices for thetreatment of musculoskeletal disorders, and more particularly to asurgical system and method for treating a spine.

BACKGROUND

Spinal pathologies and disorders such as degenerative, isthmic andiatrogenic spondylolisthesis, degenerative disc disease, disc hemiation,and stenosis may result from disease and degenerative conditions causedby injury, prior surgery and aging. These spinal disorders typicallyresult in symptoms including deformity, pain, nerve damage, and partialor complete loss of mobility. Kyphosis and lysthesis or anteriortranslation of one vertebra in relation to the next may occur in many ofthese conditions and pathologies.

Non-surgical treatments, such as medication, rehabilitation and exercisecan be effective, however, may fail to relieve the symptoms associatedwith these disorders. Current evidence based surgical treatment of thesespinal disorders includes decompression and restoration of the normalalignment of the spine with concomitant fusion. Techniques used tocommonly achieve these goals may include laminectomy, discectomy,internal spinal fixation, correction of the kyphotic deformity and theinsertion of implantable interbody prosthetics. As part of thesesurgical treatments, spinal constructs, such as, for example, bonefasteners, spinal rods and interbody devices can be used to activelycorrect the pre-existing kyphosis and vertebral translational deformityand to ultimately provide stability to a treated region. For example,during surgical treatment, interbody implants and spinal pedicle screwscan be used in concert to correct the abnormal alignment of the spinalvertebrae and provide stability serving to immobilize the spinal motionsegment, and with bone graft, will eventually result in a stable fusion.This disclosure describes an improvement in the ability to use interbodyand posterior pedicle screw implants to correct spinal kyphotic andtranslational alignment over prior technologies.

SUMMARY

In one embodiment, a method for treating a spine is provided. The methodcomprises the steps of disposing an interbody implant adjacent aposterior portion of an intervertebral disc space; connecting a surgicalinstrument with at least one fixation element fastened with tissueadjacent the posterior portion; and manipulating the surgical instrumentsuch that tissue adjacent the posterior portion engages the interbodyimplant and one or more vertebra rotate about the interbody implant. Insome embodiments, spinal implants, surgical instruments and systems areprovided.

In one embodiment, the method comprises the steps of: disposing aninterbody implant in a transverse orientation within the posterior mostportion of a surgically evacuated intervertebral disc space; connectingsurgical instruments to sagittal angulating pedicle screws fastened tothe adjacent vertebrae; and manipulating the surgical instrument suchthat the posterior portion of the vertebral body endplates engage theinterbody implant and one or more vertebra rotate about the interbodyimplant; thus correcting sagittal misalignment of the vertebrae. In someembodiments, the intervertebral interbody spinal implant is inserted ina transverse orientation within the posterior most portion of thesurgically evacuated disc space and it is rotated in the transverseplane so as to reduce a degree of anterior translation of the uppervertebra in relation to the lower.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more readily apparent from thespecific description accompanied by the following drawings, in which:

FIG. 1 is a plan view of a spine to be treated with one embodiment of asystem in accordance with the principles of the present disclosure;

FIG. 2 is a lateral view of the spine shown in FIG. 1;

FIG. 3 is an axial view of the spine shown in FIG. 1;

FIG. 4 is a plan view of components of one embodiment of a system inaccordance with the principles of the present disclosure disposed withvertebrae;

FIG. 5 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 6 is a side view of the components and vertebrae shown in FIG. 5;

FIG. 7 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 8 is a side view of the components and vertebrae shown in FIG. 7;

FIG. 9 is a side view of the components and vertebrae shown in FIG. 7;

FIG. 10 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 11 is a side view of the components and vertebrae shown in FIG. 10;

FIG. 12 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 13 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 14 is a side view of the components and vertebrae shown in FIG. 13;

FIG. 15 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 16 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 17 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 18 is a perspective view of components of one embodiment of asystem in accordance with the principles of the present disclosure;

FIG. 19 is a side view of the components shown in FIG. 18;

FIG. 20 is a side view of components of one embodiment of a system inaccordance with the principles of the present disclosure;

FIG. 21 is a plan view of components of one embodiment of a system inaccordance with the principles of the present disclosure disposed withvertebrae;

FIG. 22 is a plan view of components of one embodiment of a system inaccordance with the principles of the present disclosure disposed withvertebrae;

FIG. 23 is a perspective view of components of one embodiment of asystem in accordance with the principles of the present disclosure;

FIG. 24 is a side view of the components shown in FIG. 23;

FIG. 25 is a side view of the components shown in FIG. 23;

FIG. 26 is a perspective view of the components shown in FIG. 23;

FIG. 27 is a break away side view of components of one embodiment of asystem in accordance with the principles of the present disclosuredisposed with vertebrae;

FIG. 28 is a side view of the components and vertebrae shown in FIG. 27;

FIG. 29 is a perspective view of components of one embodiment of asystem in accordance with the principles of the present disclosure;

FIG. 30 is a side view of components of one embodiment of a system inaccordance with the principles of the present disclosure;

FIG. 31 is a side view of the components shown in FIG. 30;

FIG. 32 is a side view of components of one embodiment of a system inaccordance with the principles of the present disclosure;

FIG. 33 is a side view of components of one embodiment of a system inaccordance with the principles of the present disclosure; and

FIG. 34 is a side view of components of one embodiment of a system inaccordance with the principles of the present disclosure.

DETAILED DESCRIPTION

The exemplary embodiments of the surgical system and related methods ofuse disclosed are discussed in terms of medical devices for thetreatment of musculoskeletal disorders and more particularly, in termsof a surgical system including a spinal implant and a method fortreating a spine. In one embodiment, the systems and methods of thepresent disclosure are employed with a spinal joint fusion, for example,with a cervical, thoracic, lumbar and/or sacral region of a spine. Inone embodiment, the spinal implant includes an interbody device,sagittal angulating pedicle screws (SAS), spinal rods and/or bonefasteners.

In some embodiments, the present system is employed with osteotomytechniques and interbody concepts to aid in achieving incremental lumbarlordosis during posterior degenerative fusion procedures. In someembodiments, the present system is employed to optimize segmentallordosis in a trans-foraminal lumbar interbody fusion (TLIF).

In some embodiments, the present system is employed to provide sagittalbalance with a resultant improvement in health related quality of lifeoutcomes and the proposed prevention and/or reduction of the incidenceof adjacent segment degeneration or proximal junctional kyphosis (PJK).In some embodiments, the present system is employed with a TLIF fortreating spondylolithesis and other degenerative conditions. In someembodiments, the present system is employed with a TLIF to achieveconsistent, measured lordosis in a spinal segment to be corrected andfused, and/or resist and/or prevent inducement of kyphosis. In someembodiments, the present system is employed to utilize the strengthproperties of a postero-lateral portion of a vertebral endplate adjacentto the pedicles, which resists and/or prevents subsidence of theinterbody implant and kyphosis.

In some embodiments, the present system includes a spinal implantcomprising an interbody cage that is positioned transversely and rotatedin the transverse plane to optimally achieve lordosis, preventsubsidence, and achieve fusion. The location of the implant in atransverse and posterior position in an intervertebral disc spacepositions the implant on the strong portion of a vertebral endplatewhile preserving the central and anterior portions of the intervertebralspace for bone grafting, biological fusion enhancement, and ultimatefusion. In some embodiments, the present system optimally positions aninterbody cage and achieves an optimal measured lordosis of a vertebralsegment level with selected interbody cages and surgical instrumentsthat can be employed with open and minimally invasive surgicalprocedures.

In some embodiments, the present system includes a surgical instrument,such as, for example, a three dimensional interbody cage positioner androtator. In some embodiments, the present system is employed with amethod such that an interbody cage is placed in an intervertebral spacefrom a posterior access and then rotated to a position situatedtransversely from approximately pedicle to pedicle along a posterior,one-third of a vertebral endplate thus contacting a portion of theendplate that is resistant to subsidence and forming an effectivefulcrum for the mechanical creation of lordosis. In some embodiments,the method includes the step of a second rotation such that the cage isrotated in an axial plane, thus the rotation of the cage reduces thedegree of the spondylolisthesis as an inferior end plate is pulled backdorsally during the rotation maneuver. In some embodiments, this stepindirectly enlarges and decompresses the foramen.

In some embodiments, the present system includes one or more surgicalinstruments, such as, for example, extenders that effectively extend thelength of a beam, such as, for example, a SAS portion of a leverconfiguration and improve the mechanical advantage of the lever byincreasing a distance from a fulcrum, such as, for example, an interbodycage to a pivot point of vertebrae and/or components of the system. Insome embodiments, this configuration optimizes lordosis. In someembodiments, a posterior tether connects the extenders and can be slidventrally towards an interbody cage, thus increasing an angle betweenthe extenders and directly increasing lordosis. In some embodiments, thecomponents of the system are connected to a sliding lordosis gauge. Insome embodiments, the lordosis gauge enables an intra-operative directverification of a degree of lordosis achieved between the pedicle screwsand the vertebrae into which they are inserted.

In some embodiments, the present system includes one or more surgicalinstruments, such as, for example, a cork screw tether, which may beemployed with either an open or a minimally invasive approach and thatgradually advances a wedge between the extenders in a posteriordirection through a cork screw mechanism. As such, an intervertebraldisc space is distracted and lordosis is increased at the same time. Insome embodiments, the interbody cage is then placed with no instrumentsobstructing the intervertebral disc space. In some embodiments, thepresent system includes one or more surgical instruments, such as, forexample, a lordosis gauge that can be placed to measure a magnitude oflordosis achieved. In some embodiments, the present system is employedsuch that its components provide access for bone graft and biologicsinto an anterior aspect of the intervertebral disc space to facilitatefusion and medical imaging for interpretation of fusion. In someembodiments, the present system includes one or more bone fasteners,such as, for example, a 4.75 or 5.5 millimeters (mm) SAS. In someembodiments, the SAS can be employed for percutaneous applications.

In some embodiments, the present system is employed with a method fortreating various indications for arthrodesis in a degenerative lumbarspine, such as, for example, a single level lumbar arthrodesis fordegenerative lumbar spondylolisthesis (DLS), isthmic spondylolisthesis(IS) and iatrogenic post-surgical spondylolisthesis, which may includevertebral segments instrumented at any thoracic or lumbar segments butmost commonly at the L4-L5 and L5-SI inter-vertebral motion segment. Insome embodiments, the present system and method are employed to providedirect neurological element decompression. In some embodiments, thepresent system and method are employed to provide indirect decompressionthrough restoration of foraminal height, increased disc height andreduction of the degree of lysthesis. In some embodiments, the presentsystem and method are employed to provide solid bony arthrodesis, whichmay be achieved through intertody anterior load sharing. In someembodiments, the present system and method are employed to providerestoration of segmental lordosis. In some embodiments, the presentsystem and method are employed to provide improvement in lumbar lordosisand/or pelvic incidence ratio, for example, when there is apre-operative mismatch. In some embodiments, the present system andmethod are employed to provide a superior endplate of L4 vertebra as anapex of the lumbar lordosis and horizontal on a standing radiographicmedical image. In some embodiments, the present system and method areemployed to provide lordosis at L4-L5 vertebrae at approximately 20degrees and at L5-S1 vertebrae at approximately 25 degrees. In someembodiments, the present system and method are employed to providesegmental lordosis at a single level in a range of approximately 20through 25 degrees.

In some embodiments, the present system is employed with a method fortreating L4-L5 vertebrae degenerative, isthmic or iatrogenicspondylolisthesis. In some embodiments, the present system is employedwith a method that employs a posterior approach. In some embodiments,the posterior approach may include a posterior midline approach usedwhen a central spinal canal requires decompression or based upon surgeonpreference. In some embodiments, the posterior approach may include aposterior bilateral Wiltse muscle splitting approaches. In someembodiments, the posterior approach may include a posterior minimallyinvasive approach through which superior and inferior facets areaccessible or not.

In some embodiments, Wiltse and posterior minimally invasive approachesmay be used together; one on one side and one on the other of a spine.In some embodiments, the present system includes posterior pedicle screwinstrumentation that is inserted at a single affected motion segment,for example, four screws in two adjacent vertebrae. In some embodiments,the posterior pedicle screw instrumentation may be used at severaladjacent or non-contiguous motion segments. In some embodiments, themethod includes the step of a postero-lateral disc resection through aninterval created by resecting the superior and inferior facets on one orboth sides. In some embodiments, a trans-foraminal insertion of aninterbody implant with bone with or without biologics such that theinterbody implant is inserted in the disc space to obtain an interbodyarthrodesis. In some embodiments, the present system and method areemployed to provide up to 25 degrees of lordosis at a single vertebrallevel.

In some embodiments, the present system includes an interbody cage thatis positioned transversely and resting on the posterior third of avertebral endplate, for example, in a region adjacent to the pedicles toresist subsidence. In some embodiments, the present system includes aninterbody cage having a clover-leaf design that loads a postero-lateralportion of a vertebral end plate adjacent to the pedicles. In someembodiments, the present system includes bone graft that is placedanteriorly and is easily visualized post-operatively facilitating theassessment of fusion status. In some embodiments, the method includesplacing the bone graft anteriorly such that the bone graft is lesslikely to extrude and displace back into the spinal canal or neuralforaminae.

In some embodiments, the present system includes one or more bonefasteners, such as, for example, fixed-angle-screws (FAS), which have aconstrained 90 degree angle between the screw shaft and a spinal rod. Insome embodiments, the spinal rod is contoured into lordosis such thattightening the FAS orients the screw shaft and the spinal rod to the 90degree angle to create an anterior column distraction. In someembodiments, the present system and method include selecting anoperating room table and positioning of a patient with hips extended toimprove lordotic alignment. In some embodiments, the present system andmethod include placement of the cage transversely in the dorsalone-third of the disc space leaving space within the disc space for bonegraft and biologics.

In some embodiments, the present system is employed with a methodincluding the steps of inserting the cage and disc shavers in a firstvertical position, for example via straight access, and then rotatingthe cage 90 degrees to a horizontal or transverse position to minimizeroot retraction and trauma, for example, of the exiting nerve root. Insome embodiments, this configuration is effective at reducing the degreeof the spondylolisthesis; restoring disk height; and correcting lateralrotatory lysthesis. In some embodiments, this configuration positionsthe cage in an optimal area of the vertebral endplate from a strengthprofile and achieves lordosis. In some embodiments, the present systememploys factors, such as, for example, the location of the cage on theendplate, resistance to subsidence and the technique of posteriorosteotomy correction to determine sagittal alignment.

In some embodiments, the present system comprise spinal implantsincluding interbody cages that can be modified based on one or more ofheight, width, length, type and quality of implant bone interface, theposition of the cage on the vertebral body endplate, and/or the methodof cage insertion.

In some embodiments, the present system comprises an interbody cageincluding a posteriorly placed transversely oriented dumbbell shapedcage that is placed through a surgical instrument, such as, for example,a three dimensional insertion device. In some embodiments, the cagecomprises a dumbbell shape and is inserted from one side in a verticalaccess direction with a TLIF technique. In some embodiments, once in thedisc space, the cage rotates around a horizontal axis into a transverseorientation in the disc space at the back of the vertebral endplate,which may comprise a final resting position.

In some embodiments, the method employed for placement of the cageincludes placing the cage in a transverse position so that it is locatedon the posterior one-third of the vertebral endplate where the bone ismost resistant to subsidence. In some embodiments, the cage extends tospan from the lateral margin of one pedicle to the lateral margin of theother pedicle. In some embodiments, the final position of the cage istransverse and spans the two strongest portions of the endplate. In someembodiments, the cage is wider than it is high and in some cases from8-10 mm in height and functions as a fulcrum. In some embodiments, thecage, which is located across the posterior portion of theintervertebral space, is not oversized, and as the cage restoresposterior intervertebral height it also by necessity enlarges theintervertebral foraminae. By virtue of the posterior and transverseposition of the cage, this foraminal restoration is maintainedthroughout the processes of compression between the screw heads andlordosis. In some embodiments, the method includes inserting bone graftand biologics anteriorly into the intervertebral space prior to andafter the insertion of the cage.

In some embodiments, the present system comprises an interbody cageincluding a transversely rotating cage placed through a surgicalinstrument, such as, for example, a three dimensional insertion device.In some embodiments, the method includes the step, after entrance intothe disc space posteriorly, as described herein, of rotating the cage,as described herein. In some embodiments, the method includes the stepof a second rotation by rotating the cage from a horizontal to avertical orientation. In some embodiments, the rotation is facilitatedby the insertion device, as described herein. In some embodiments, therotation around a transverse axis achieves an increase in intervertebralheight between the two endplates posteriorly, thus creating an effectivepivot point which enables the pedicle screws to function as a simplelever arm, and by rotating in the direction opposite to the direction ofthe antero-listhesis, the degree of the spondylolisthesis is reduced. Insome embodiments, the shape of the cage comprises a narrow I-beam thatis inserted into an intervertebral disc space in a flat position, thusminimizing the potential interference with the exiting nerve root. Insome embodiments, once rotated, the cage is situated transversely acrossthe posterior portion of the endplate, as described herein.

In some embodiments, the present system includes a surgical instrument,such as, for example, a dynamic insertion instrument that enablesinsertion of the cage into the intervertebral disc in a straight-aheadaccess. In some embodiments, after insertion, the method includes afirst active maneuver that angulates the cage to position ittransversely. In some embodiments, the surgical instrument comprises apivoting control set of levers. In some embodiments, the method includesa second rotation maneuver that enables an increase in the cage heightand reduction of the spondylolisthesis. In some embodiments, theinsertion instrument rotates the cage with a planetary gear-train, whichgives a practitioner a mechanical advantage while allowing thepractitioner to perform fine adjustments during the rotation maneuver.

In some embodiments, the present system comprises an interbody cageincluding a posteriorly expanding cage. In some embodiments, theexpanding cage is employed with a method such that the expanding cage isinserted transversely into the intervertebral space, as describedherein. In some embodiments, the surgical instrument comprises aninserter having pivoting levers within the inserter handle to enable thecage to be inserted longitudinally and then angled into a transverseposition, as described herein. In some embodiments, once the expandingcage is optimally positioned, as described herein, the expanding cagecan increase in height through deploying an expanding screw thread. Insome embodiments, the expanding cage includes an implant-endplateinterface designed to optimize resistance to subsidence. In someembodiments, the expanding cage is positioned with a posterior positionof an intervertebral space to allow for access to the intervertebralspace to place biologics and bone graft into the desired anterior aspectof the disc space.

In some embodiments, the present system comprises one or more surgicalinstruments that utilize bone fasteners, such as, for example, a SAS andscrew extenders. In some embodiments, multi-axial screws may be employedwith the present system.

In some embodiments, the surgical instrument comprises a lever thatachieves predictable and measurable lordosis by posterior compression ofscrew extenders over a posteriorly placed cage acting as a fulcrum. Insome embodiments, the lever is used after the cage is placed. In someembodiments, the lever can be used with open or minimally invasiveapproaches.

In some embodiments, the lever is employed with a method that achievessegmental lordosis through use of a posterior implant and technique thatactively controls sagittal alignment. In some embodiments, the leveractively controls the sagittal alignment of the vertebrae whileextending the effectiveness of the lever arm and improving themechanical advantage of a kyphosis correction maneuver. In someembodiments, the lever is employed with a method using a SAS andextenders with a posteriorly placed cage so that cage position isoptimized and resistance to subsidence is provided. In some embodiments,this configuration lengthens the lever arm and leaves space for bonegraft anterior to the cage.

In some embodiments, the lever is connected to a lordosis gauge at anapex of the extenders to accurately measure an intra-operative lordosisachieved. In some embodiments, the apex can be moved closer to the cageby overlapping the extenders and thus shortening the lever arm. In someembodiments, this configuration increases the lordosis achieved and isfacilitated by a corkscrew type mechanism that shifts the apex of theextenders ventrally, thus increasing the measurable lordosis angle.

In some embodiments, the extender-lever is attached to a SAS. In someembodiments, the lever is employed with a method using a flat extenderwith a channel. In some embodiments, the lever is employed with a methodthat distracts the disc space with a fixture attached to the end of theextenders. In some embodiments, the channel enables tethering with asliding bolt connector with a goniometer or protractor gauge. In someembodiments, the protractor enables a practitioner to verify the degreeof lordosis achieved intra-operatively. In some embodiments, the use ofextenders effectively extends the length of the pedicle screw portion ofthe lever and improves the mechanical advantage of the lever byincreasing the distance from the fulcrum (cage) to the pivot point.

In some embodiments, the surgical instrument comprises a cork screwtether, which includes a posterior tethering of extenders to graduallydistract an intervertebral disc space in lordotic alignment prior tocage placement using a cork screw controlled wedge held between thescrew extenders. In some embodiments, the cork screw tether is usedprior to cage placement. In some embodiments, the cork screw tether canbe used with open or minimally invasive approaches.

In some embodiments, the cork screw tether is employed with a method todistract an intervertebral disc space while creating lordosis. In someembodiments, after the screws are placed, a posterior tether is createdbetween the screw extenders, for example, on both sides of vertebraeusing four screws and two cork screw tethers. In some embodiments, thereis a wedge disposed between the extenders that is actively movedposteriorly in a controlled manner with a cork screw device. In someembodiments, this configuration actively distracts the vertebrae whileincreasing lordosis. In some embodiments, the method includes facet anddisc space releases and spinous process osteotomies to facilitatelordosing distraction. In some embodiments, the cork screw tetherincludes a goniometer or protractor gauge, as described herein. In someembodiments, combining a bolt-type extender with the threaded tethercorkscrew enables the tether to be actively advanced down the channel inthe extender, for example, with a cork screw type mechanism, and thusmove the tether of the two extenders closer to the fulcrum, for example,an interbody cage and thus increase the lordosis achieved. In someembodiments, the cork screw tether includes a threaded corkscrew handlethat can be rotated to incrementally advance the tether down the shaftof the extenders.

In some embodiments, the cork screw tether is employed with a minimallyinvasive approach and by rotating the cork screw, the tether is advancedventrally thus increasing the angular kyphosis between the extenders. Insome embodiments, the cork screw tether is employed with a minimallyinvasive approach and the cork screw tether can pull a wedge dorsallybetween the extenders in a posterior direction while maintaining theposterior tether thus distracting the disc space and increasinglordosis. In some embodiments, a lordosis gage can be placed to measurethe magnitude of lordosis achieved.

In some embodiments, the three dimensional cage positioner and rotatoris employed with a method such that a cage is placed from a posterioraccess and then rotated transverse from the pedicles along the posteriorone third of the endplate thus contacting the part of the endplate thatis most resistant to subsidence and forming an effective fulcrum for themechanical creation of lordosis. In some embodiments, the methodincludes the step of a second rotation such that the cage is rotated inan axial plane. As such, the rotation of the cage reduces the degree ofthe spondylolisthesis as the inferior endplate is pulled back dorsallyduring the rotation maneuver, which decompresses the foramen.

In some embodiments, the present system and method can be employedthrough midline exposures, minimally invasive percutaneous and/orlateral Wiltse type incisions, which may include percutaneous systemscomprising SAS and extenders. In some embodiments, the present systemand method can be employed with a resection of the kissing portion ofthe posterior spinous processes to facilitate lordosis and enable thesliding of the extender tether ventrally. In some embodiments, thepresent system and method can be employed with a small midline incisionto apply an opto-electronic marker array to the spinous processes forsurgical navigation. In some embodiments, through the same incision, theadjacent portions of the spinous processes may be resected to preventimpingement of the spine and inhibition of lordosis.

In some embodiments, the present system includes an interbody cagehaving a surface, which contacts the vertebral endplate to optimize thebone-implant interface. In some embodiments, the interbody cage surfacedoes not include sharp edges or serrations and may include aninterference fit to facilitate porous bony ingrowth. In someembodiments, the method includes disposing bone graft ventral in theanterior and middle third of the intervertebral disc space and thusdirect radiographic evidence of fusion as seen on lateral post-operativeradiographs.

In some embodiments, the present system includes right-angleddown-biting ring and cupped curettes to facilitate safe disc removaltransversely across the posterior portion of the intervertebral discspace. In some embodiments, the present system includes markers on thesurgical instruments to resist and/or prevent placement into the spinalcanal and/or outside the protective annulus of the intervertebral disc.

In some embodiments, the present system includes angled ronguers forremoval of intervertebral disc tissue. In some embodiments, the presentsystem includes ring and cupped curettes for anterior disc tissueremoval and separate angled instruments for posterior disc tissueremoval. In some embodiments, the present system includes a distractorto facilitate anterior release of the intervertebral disc space, forexample, for deformity correction. In some embodiments, the presentsystem includes rod benders and pre-contoured rods with increaseddiameter bends to facilitate lordosis. In some embodiments, the presentsystem is employed with a method to treat single level degenerativeapplications and utilize 4.75 and 5.5 mm bone fasteners. In someembodiments, the present system is employed with a method employing aSAS for percutaneous applications. In some embodiments, the presentsystem is employed with a method employing lever extenders, corkscrewextenders and gauges that can be used with 4.75 mm and 5.5 mm bonefasteners. In some embodiments, the present system is employed with amethod employing transversely placed posterior endplate cages. In someembodiments, the cages can include expanding cages,insert-angulate-and-rotate cages, and/or cages connected with an angledinserter.

In some embodiments, the present system and method are employed foroptimizing segmental lordosis in TLIF procedures. In some embodiments,the present system is employed with a method comprising the steps of:placing an interbody fusion implant laterally in the posterior one-thirdof an intervertebral disc space via a unilateral TLIF approach; using asurgical instrument attached to posterior fixation elements, such as,for example, pedicle screws and/or screw extenders, to exert acompressive force on the interbody fusion implant; and using theinterbody fusion implant as a posterior fulcrum to achieve segmentallordosis at the fusion level.

In some embodiments, the present system may include allograft and/orother bone growth promoting material. In some embodiments, the presentsystem may include allograft and/or other bone growth promotingmaterial, which may be added via a TLIF approach and packed into anintervertebral disc space anterior to an interbody fusion implant. Insome embodiments, the present system may include an interbody fusionimplant that comprises a cylindrical barbell shape. In some embodiments,the present system may include an interbody fusion implant thatcomprises a taller than wide rectangular box or I-beam shape. In someembodiments, the present system may include an interbody fusion implantthat comprises an expandable height implant.

In some embodiments, the present system is employed with a methodcomprising the steps of: inserting one or more interbody fusionimplants, rotating the implants; and exerting a compressive lordosingforce on posterior screws. In some embodiments, the present system isemployed with a method comprising the steps of: placing alaterally-oriented TLIF implant, such as, for example, a banana-shapedcage, on the posterior one-third of the vertebral endplate to introducelordosis at any one spinal segment. In some embodiments, the presentsystem includes specialized surgical instruments for inserting theimplants, rotating the implants and exerting a compressive lordosingforce on posterior screws.

The present disclosure may be understood more readily by reference tothe following detailed description of the embodiments taken inconnection with the accompanying drawing figures, which form a part ofthis disclosure. It is to be understood that this application is notlimited to the specific devices, methods, conditions or parametersdescribed and/or shown herein, and that the terminology used herein isfor the purpose of describing particular embodiments by way of exampleonly and is not intended to be limiting. Also, in some embodiments, asused in the specification and including the appended claims, thesingular forms “a,” “an,” and “the” include the plural, and reference toa particular numerical value includes at least that particular value,unless the context clearly dictates otherwise. Ranges may be expressedherein as from “about” or “approximately” one particular value and/or to“about” or “approximately” another particular value. When such a rangeis expressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. It isalso understood that all spatial references, such as, for example,horizontal, vertical, top, upper, lower, bottom, left and right, are forillustrative purposes only and can be varied within the scope of thedisclosure. For example, the references “upper” and “lower” are relativeand used only in the context to the other, and are not necessarily“superior” and “inferior”.

As used in the specification and including the appended claims,“treating” or “treatment” of a disease or condition refers to performinga procedure that may include administering one or more drugs to apatient (human, normal or otherwise or other mammal), employingimplantable devices, and/or employing instruments that treat thedisease, such as, for example, micro discectomy instruments used toremove portions bulging or herniated discs and/or bone spurs, in aneffort to alleviate signs or symptoms of the disease or condition.Alleviation can occur prior to signs or symptoms of the disease orcondition appearing, as well as after their appearance. Thus, treatingor treatment includes preventing or prevention of disease or undesirablecondition (e.g., preventing the disease from occurring in a patient, whomay be predisposed to the disease but has not yet been diagnosed ashaving it). In addition, treating or treatment does not require completealleviation of signs or symptoms, does not require a cure, andspecifically includes procedures that have only a marginal effect on thepatient. Treatment can include inhibiting the disease, e.g., arrestingits development, or relieving the disease, e.g., causing regression ofthe disease. For example, treatment can include reducing acute orchronic inflammation; alleviating pain and mitigating and inducingre-growth of new ligament, bone and other tissues; as an adjunct insurgery; and/or any repair procedure. Also, as used in the specificationand including the appended claims, the term “tissue” includes softtissue, muscle, ligaments, tendons, cartilage and/or bone unlessspecifically referred to otherwise.

The following discussion includes a description of a surgical system andrelated methods of employing the surgical system in accordance with theprinciples of the present disclosure. Alternate embodiments are alsodisclosed. Reference is made in detail to the exemplary embodiments ofthe present disclosure, which are illustrated in the accompanyingfigures. Turning to FIGS. 1-11, there are illustrated components of asurgical system, such as, for example, a spinal implant system 10.

The components of spinal implant system 10 can be fabricated frombiologically acceptable materials suitable for medical applications,including metals, synthetic polymers, ceramics and bone material and/ortheir composites. For example, the components of spinal implant system10, individually or collectively, can be fabricated from materials suchas stainless steel alloys, commercially pure titanium, titanium alloys,Grade 5 titanium, superelastic titanium alloys, cobalt-chrome alloys,stainless steel alloys, superelastic metallic alloys (e.g., Nitinol,super elasto-plastic metals, such as GUM METAL®), ceramics andcomposites thereof such as calcium phosphate (e.g., SKELITE™),thermoplastics such as polyaryletherketone (PAEK) includingpolyetheretherketone (PEEK), polyetherketoneketone (PEKK) andpolyetherketone (PEK), carbon-PEEK composites, PEEK-BaSO₄ polymericrubbers, polyethylene terephthalate (PET), fabric, silicone,polyurethane, silicone-polyurethane copolymers, polymeric rubbers,polyolefin rubbers, hydrogels, semi-rigid and rigid materials,elastomers, rubbers, thermoplastic elastomers, thermoset elastomers,elastomeric composites, rigid polymers including polyphenylene,polyamide, polyimide, polyetherimide, polyethylene, epoxy, bone materialincluding autograft, allograft, xenograft or transgenic cortical and/orcortiocancellous bone, and tissue growth or differentiation factors,partially resorbable materials, such as, for example, composites ofmetals and calcium-based ceramics, composites of PEEK and calcium basedceramics, composites of PEEK with resorbable polymers, totallyresorbable materials, such as, for example, calcium based ceramics suchas calcium phosphate such as hydroxyapatite (HA), corraline HA, biphasiccalcium phosphate, tricalcium phosphate, or fluorapatite, tri-calciumphosphate (TCP), HA-TCP, calcium sulfate, or other resorbable polymerssuch as polyaetide, polyglycolide, polytyrosine carbonate,polycaroplaetohe and their combinations, biocompatible ceramics,mineralized collagen, bioactive glasses, porous metals, bone particles,bone fibers, morselized bone chips, bone morphogenetic proteins (BMP),such as BMP-2, BMP-4, BMP-7, rhBMP-2, or rhBMP-7, demineralized bonematrix (DBM), transforming growth factors (TGF, e.g., TGF-β), osteoblastcells, growth and differentiation factor (GDF), insulin-like growthfactor 1, platelet-derived growth factor, fibroblast growth factor, orany combination thereof.

Various components of spinal implant system 10 may have materialcomposites, including the above materials, to achieve various desiredcharacteristics such as strength, rigidity, elasticity, compliance,biomechanical performance, durability and radiolucency or imagingpreference. The components of spinal implant system 10, individually orcollectively, may also be fabricated from a heterogeneous material suchas a combination of two or more of the above-described materials. Thecomponents of spinal implant system 10 may be monolithically formed,integrally connected or include fastening elements and/or instruments,as described herein. In one embodiment, a spinal implant, as describedherein, may be formed substantially of a biocompatible metal, such astitanium and selectively coated with a bone-growth promoting material,such as HA. In one embodiment, a spinal implant, as described herein,may be formed substantially of a biocompatible polymer, such as PEEK,and selectively coated with a biocompatible metal, such as titanium, ora bone-growth promoting material, such as HA. In some embodiments,titanium may be plasma sprayed onto surfaces of the spinal implant tomodify a radiographic signature of the spinal implant and/or improvebony ongrowth to the spinal implant by application of a porous orsemi-porous coating of titanium.

Spinal implant system 10 may be employed, for example, with minimallyinvasive procedures, including percutaneous techniques, mini-opensurgical techniques and/or open surgical techniques to deliver andintroduce instrumentation and/or spinal implants, such as, for example,an interbody implant, such as, for example, a cage 12, as shown in FIG.7, at a surgical site within a body of a patient, which includes, forexample, vertebrae V. In some embodiments, spinal implant system 10 caninclude spinal constructs including one or more bone fasteners, such as,for example, SAS 14, spinal rods 16, tethers, connectors, plates and/orinstruments, as described herein. In some embodiments, variouscomponents of spinal implant system 10 may be utilized in open ortraditional spinal surgical techniques. In some embodiments, spinalimplant system 10 is employed to achieve consistent, measured lordosisin a spinal segment of vertebrae V to be corrected and fused, and/orresist and/or prevent inducement of kyphosis. In some embodiments,spinal implant system 10 is employed to utilize the strength propertiesof a posterior and/or postero-lateral portion of a vertebral endplate ofvertebrae V adjacent to the pedicles, which resists and/or preventssubsidence and kyphosis.

In some embodiments, spinal implant system 10 is employed with a TLIFsurgical approach, technique or procedure, which utilizes an opening inbone, such as, for example, foramina between a vertebral body, such as,for example, vertebra L4 and a vertebral body, such as, for example,vertebra L5, as shown in FIGS. 1 and 2. While some examples shown hereindepict L4 and L5, it should be understood that the various embodimentscould be used in procedures for the treatment of any selected levels ofthe human spine, including the cervical spine, thoracic spine and/orlumbar spine (including but not limited to the L5-S1 (lumbosacral) discspace. In some embodiments, a patient is positioned in a prone position.In some embodiments, the TLIF procedure includes aninter-muscular/Wiltse approach such that adjacent muscle is dissected.In this approach, a para-spinal incision is made to provide exposure tothe surgical site, such as, for example, a lumbo-sacral junction. Insome embodiments, spinal implant system 10 is employed with a patient ina prone position, and/or employed with various additional surgicalapproaches to the spine, including anterior, posterior, posteriormid-line, direct lateral, postero-lateral, and/or antero lateralapproaches.

In some embodiments, in connection with the TLIF procedure, a medicalpractitioner makes and/or creates an incision in tissue, which includessoft tissue and/or muscle, to obtain access to a surgical site includingvertebral levels L4, L5. Retractor 22, as shown in FIG. 4, is insertedthrough the incision and disposed with the tissue. Blades 24 ofretractor 22 engage and space the tissue to create a surgical pathwayand/or opening SO to the surgical site, which includes a surgicalpathway SP, as shown in FIG. 3, employed with the TLIF surgicalapproach.

Once access to the surgical site is obtained, a surgical procedure, asdescribed herein, is performed for treating the spine disorder. Thediseased and/or damaged portion of vertebrae V, which may includediseased and/or damaged intervertebral disc tissue, are removed tocreate a vertebral space between vertebrae L4, L5.

In some embodiments, pilot holes are made in selected vertebra ofvertebrae V for receiving fixation elements, such as, for example, bonefasteners. For example, each of SAS 14 is inserted or otherwise engagedwith each of vertebrae L4, L5. In some embodiments, spinal constructsincluding rods 16 are employed as provisional and/or working rods tosupport vertebrae V during a surgical procedure. One or more rods 16 areconnected and reduced with receivers of SAS 14 to provide support andstabilization of vertebrae L4, L5. In some embodiments, spinal implantsystem 10 may include one or a plurality of the spinal constructs. Insome embodiments, the plurality of spinal constructs may be disposed invarious alternate orientations, such as, for example, side by side,parallel, transverse and/or other angular orientations such as acute orobtuse, co-axial and/or may be offset or staggered. In some embodiments,the plurality of spinal constructs including rods 16 may provide atemplate configuration for permanently implantable spinal rods, such as,implantable, final, permanent, removable, non-removable, bio-absorbable,resorbable and/or bio-degradable, and/or comprise permanentlyimplantable spinal rods.

A preparation instrument (for example, as shown in FIGS. 20 and 21) isemployed to remove disc tissue, fluids, adjacent tissues and/or bone,and scrape and/or remove tissue from endplate surfaces E1 of vertebra L4and/or endplate surface E2 of vertebra L5. Vertebral facets, such as,for example, an L4 inferior facet and an L5 superior facet are resected,as shown in FIG. 5. A trans-foraminal discectomy is performed to createvertebral space S between vertebral bodies L4, L5 leaving a portion ofan anterior ligament AL, as shown in FIG. 6.

In some embodiments, the size of cage 12 is selected after trialing. Insome embodiments, cage 12 is visualized by fluoroscopy and orientedbefore introduction into vertebral space S. A surgical instrument, suchas, for example, an inserter (not shown) is connected with cage 12 fordisposal in an introduction or delivery orientation for alignment ofcage 12 with the surgical pathway SP such that cage 12 is steerable tovertebral space S between vertebrae L4, L5. In some embodiments,manipulation of the inserter rotates and/or steers cage 12. Cage 12 isselectively positioned to an implantable orientation adjacent aposterior portion P of vertebral space S between vertebrae L4, L5, asshown in FIG. 7.

Cage 12 is inserted into vertebral space S between vertebrae L4, L5 tore-establish and maintain disc height. Cage 12 is disposed posteriorlywithin vertebral space S adjacent posterior portion P and the pediclesof vertebrae L4, L5. In some embodiments, this configuration of cage 12and selective orientation of cage 12 with vertebrae L4, L5 aligns cage12 with the portion of a vertebral endplate having a higher strength andresistance to subsidence. In some embodiments, posterior placement ofcage 12 provides space within vertebral space S for disposal of bonegraft and/or other agents, as described herein. Posterior placement ofcage 12 improves stability and decreases the risk of subsidence intotissue, as described herein. In some embodiments, cage 12 providesheight restoration between vertebral bodies, decompression, andrestoration of sagittal and/or coronal balance. In some embodiments, aninserter (not shown) is connected with cage 12 to rotate cage 12, in thedirection shown by arrow R (and/or in an opposite direction) in FIG. 9.The height of cage 12 is increased and the end surfaces of cage 12rotate into engagement with endplate surface E1 of vertebra L4 andendplate surface E2 of vertebra L5, such that surfaces E1, E2 exert acompressive force on cage 12.

In some embodiments, alignment and disposal of cage 12 with posteriorportion P orients cage 12 such that it comprises a fulcrum. The fulcrumconfiguration of cage 12 is disposed between and engages endplatesurfaces E1, E2. A surgical instrument, as described herein, isconnected with vertebrae L4, L5 to manipulate vertebrae L4, L5 such thatendplate surfaces E1, E2 adjacent posterior portion P engage cage 12,disposed in a fulcrum configuration. For example, manipulating thesurgical instrument causes endplate surfaces E1, E2 adjacent posteriorportion P to exert a compressive force on cage 12 such that cage 12comprises a posterior fulcrum during posterior compression and vertebraeL4, L5 are selectively rotated about cage 12 to achieve a measuredlordosis in the L4, L5 spinal segment.

In some embodiments, a surgical instrument 40, as shown in FIGS. 7-9, isemployed to manipulate vertebrae L4, L5. Surgical instrument 40 includeslever arms, such as, for example, extenders 26 a, 26 b. Extenders 26 a,26 b are attached with SAS 14 to manipulate vertebrae L4, L5. Surgicalinstrument 40 manipulates vertebrae L4, L5 such that endplate surfacesE1, E2 adjacent posterior portion P exert a compressive force, in thedirection shown by arrows A in FIG. 9, on cage 12 such that cage 12comprises a posterior fulcrum during posterior compression. As such,surgical instrument 40 manipulates vertebrae L4, L5 to selectivelyrotate vertebrae L4, L5, in the direction shown by arrows B in FIG. 9,about cage 12 to achieve segmental lordosis of vertebrae L4, L5. In someembodiments, surgical instrument 40 includes a lordosis gauge 28, asshown in FIG. 10, attached to extenders 26 at an apex 30 of extenders 26to measure lordosis, for example in an angular representation ofdegrees, as provided by the components of spinal implant system 10 anddescribed herein. In one embodiment, apex 30 can be adjusted byoverlapping extenders 26 to shorten/lengthen lever arms 26 a, 26 b andthe distance from vertebrae L4, L5 to increase/decrease lordosis, asshown in FIG. 11. Extenders 26 a, 26 b, as shown in FIG. 11, are shownin simple schematic form but may take the form of one or more slottedextenders that may be removably and/or selectively attached to areceiver head on SAS 14 or any other bone and/or pedicle screw.

Upon completion of a procedure, as described herein, the surgicalinstruments, assemblies and non-implanted components of spinal implantsystem 10 are removed and the incision(s) are closed. One or more of thecomponents of spinal implant system 10 can be made of radiolucentmaterials such as polymers. Radiopaque markers may be included foridentification under x-ray, fluoroscopy, CT or other imaging techniques.In some embodiments, the use of surgical navigation, microsurgical andimage guided technologies may be employed to access, view and repairspinal deterioration or damage, with the aid of spinal implant system10. In some embodiments, spinal implant system 10 may include one or aplurality of interbody implants, rods, tethers, plates, connectorsand/or bone fasteners for use with a single vertebral level or aplurality of vertebral levels. In some embodiments, spinal implantsystem 10 may include one or a plurality of bone fasteners that maycomprise multi-axial screws, sagittal angulation screws, pedicle screws,mono-axial screws, uni-planar screws, facet screws, fixed screws, tissuepenetrating screws, conventional screws, expanding screws, wedges,anchors, buttons, dips, snaps, friction fittings, compressive fittings,expanding rivets, staples, nails, adhesives, posts, fixation platesand/or posts.

In one embodiment, spinal implant system 10 includes an agent, which maybe disposed, packed, coated or layered within, on, adjacent or about thecomponents and/or surfaces of spinal implant system 10, and/or disposedwith tissue. In some embodiments, the agent may include bone growthpromoting material, such as, for example, bone graft to enhance fixationof the components and/or surfaces of spinal implant system 10 withvertebrae. In some embodiments, the agent may include one or a pluralityof therapeutic agents and/or pharmacological agents for release,including sustained release, to treat, for example, pain, inflammationand degeneration.

In one embodiment, as shown in FIGS. 12-14, surgical instrument 40,similar to that described above, includes arms 40 a, 40 b. Arm 40 aextends between an end 42 a and an end 44 a. End 42 a includes anextender 46 configured for engagement with SAS 14 at vertebra L4,similar to that described herein. End 44 a includes a flat configurationhaving a surface 48 a that defines a channel 50 a. Arm 40 b extendsbetween an end 42 b and an end 44 b. End 42 a includes an extender 46configured for engagement with SAS 14 at vertebra L5, similar to thatdescribed herein. End 44 b includes a flat configuration having asurface 48 b that defines a channel 50 b. In some embodiments, extender46 may be connected, attached or monolithically formed with arm 40 aand/or arm 40 b. In some embodiments, channel 50 a and/or channel 50 bmay have various configurations, such as, for example, oval, oblong,rectangular, polygonal, irregular, uniform, non-uniform, variable and/ortapered. Channels 50 a, 50 b are configured for movable disposal of aconnector, such as, for example, a bolt 52. Bolt 52 is translatablealong channels 50 a, 50 b, and configured to facilitate relativetranslation and/or rotation of arms 40 a, 40 b. In some embodiments,bolt 52 includes a lock for fixing relative position of arms 40 a, 40 b.

Surgical instrument 40, as shown in FIGS. 12-14, is employed tomanipulate vertebrae L4, L5. Arms 40 a, 40 b are attached with SAS 14,via extenders 46, to manipulate vertebrae L4, L5 such that endplatesurfaces E1, E2 adjacent posterior portion P exert a compressive force,in the direction shown by arrows C in FIG. 13, on cage 12 such that cage12 comprises a posterior fulcrum during posterior compression. As such,arms 40 a, 40 b manipulate vertebrae L4, L5 to selectively rotatevertebrae L4, L5, in the direction shown by arrows D in FIG. 13, aboutcage 12 to achieve segmental lordosis of vertebrae L4, L5. In someembodiments, as shown in FIG. 14, bolt 52 is configured to translatealong channels 50 a, 50 b to adjust and overlap extenders 46 toshorten/lengthen arms 40 a, 40 b and the distance from vertebrae L4, L5to increase and/or decrease an apex 54 of arms 40 a, 40 b toincrease/decrease lordosis.

In one embodiment, as shown in FIG. 15, instrument 40 includes alordosis gauge, such as, for example, a protractor 60. Protractor 60 isconfigured to facilitate determination of the degree of lordosisachieved intra-operatively. In one embodiment, protractor 60 isconfigured for attachment to bolt 52, described herein. In someembodiments, protractor 60 can connected, attached or monolithicallyformed with arms 40 a, 40 b, described herein. Protractor 60 includes anouter surface 62 that includes indicia 64 that represents and/orprovides information relating to the segmental lordosis of vertebrae L4,L5. In some embodiments, indicia 64 include markings 66 that comprise aplurality of spaced apart graduations.

Markings 66 represent and/or provide information relating to an angularrange for measuring, selecting, adjusting and/or displaying an angle abetween arms 40 a, 40 b connected with vertebrae L4, L5 connectedthereto. In some embodiments, angle a is measured in a range of 0through 40 degrees. An indicator, such as, for example, a pointer 68identifies a measured, selected, adjusted and/or displayed angle fromsurface 62. Markings 66 include bi-laterally disposed groovesequidistantly spaced apart and corresponding to measured angularincrements of indicia 64. Pointer 68 is movable relative to surface 62and markings 66 to identify a measured, selected, adjusted and/ordisplayed angle from surface 62 between vertebrae L4, L5 connectedthereto.

In some embodiments, markings 66 are disposed in increments of 10angular degrees. In some embodiments, indicia 64 may include an analog,such as, for example, a dial with a numerical indicator of angle and/ordigital display, such as, for example, LED and/or LCD. In someembodiments, indicia 64 include human readable visual indicia, such as,for example, a label, color coding, alphanumeric characters or an icon.In some embodiments, indicia 64 include human readable tactile indicia,such as, for example, raised portions, lowered portions or Braille. Insome embodiments, indicia 64 is a printed or written item in combinationwith a slot or groove, whereby the printed or written item is placed inthe slot or groove to display information. In some embodiments, indicia64 may be applied as an adhesive. In some embodiments, surface 62 isdisposed at an angular orientation, for example 90 degrees, relative toa longitudinal axis of extenders 46, such that indicia 64 is disposed atan angular orientation, for example 90 degrees, relative to thelongitudinal axis to display information to a medical practitioner. Insome embodiments, this configuration enables a surgeon with a dorsalline of sight, for example from above indicia 64, to read the displayedinformation of indicia 64.

In one embodiment, as shown in FIGS. 16 and 17, spinal implant system10, similar to the systems and methods described herein, comprises asurgical instrument 140, similar to instrument 40, described above.Surgical instrument 140 includes arms 140 a, 140 b, similar to arms 40a, 40 b, described herein. Arm 140 a extends between an end 142 a and anend 144 a. End 142 a includes an extender 146 configured for engagementwith SAS 14 at vertebra L4, similar to that described herein. End 144 aincludes a flat configuration having a surface 148 a that defines achannel 150 a. Arm 140 b extends between an end 142 b and an end 144 b.End 142 a includes an extender 146 configured for engagement with SAS 14at vertebra L5, similar to that described herein. End 144 b includes aflat configuration having a surface 148 b that defines a channel 150 b.Channels 150 a, 150 b are configured for movable disposal of a bolt 152,which is configured to facilitate relative rotation of arms 140 a, 140b. In some embodiments, bolt 152 includes a lock for fixing relativeposition of arms 140 a, 140 b.

A wedge 156 is disposed between arms 140 a, 140 b. Wedge 156 includes anend 158 and an end 159 and is tapered between ends 158, 159 to causeexpansion and/or contraction of arms 140 a, 140 b as wedge 90translates, in the direction shown by arrows G, between arms 140 a, 140b. Wedge 156 is configured to translate laterally between arms 140 a,140 b to adjust and increase and/or decrease an apex of arms 140 a, 140b and the distance from vertebrae L4, L5 to increase/decrease lordosis.

Wedge 156 is attached to an actuator 162 to translate wedge 156, in thedirection shown by arrows G. Actuator 162 includes a handle 164 and alongitudinal member, such as, for example, a tether 102. In someembodiments, as actuator 162 is rotated, tether 102 is wound abouthandle 164 such that wedge 156 is drawn and translated posteriorly withtether 102 causing wedge 156 to translate laterally between arms 140 a,140 b. As such, arms 140 a, 140 b are caused to relatively rotate. Insome embodiments, handle 164 is connected with a threaded shaft andwedge 156 includes an inner threaded surface that defines a cavity fordisposal of the threaded shaft. As actuator 162 is rotated, the threadedshaft rotates in engagement with wedge 156 such that wedge 156 istranslated posteriorly or anteriorly relative to the threaded shaftcausing wedge 156 to translate laterally between arms 140 a, 140 b torelatively rotate arms 140 a, 140 b.

Surgical instrument 140, as shown in FIGS. 16 and 17, is employed tomanipulate vertebrae L4, L5. Arms 140 a, 140 b are attached with SAS 14,via extenders 146, to manipulate vertebrae L4, L5. As actuator 162 isrotated, tether 102 is wound about handle 164 such that wedge 156 isdrawn and translated posteriorly with tether 102 causing wedge 156 totranslate laterally between arms 140 a, 140 b, as described herein. Assuch, arms 140 a, 140 b are caused to relatively rotate such thatendplate surfaces E1, E2 adjacent posterior portion P exert acompressive force, in the direction shown by arrows E in FIG. 17, oncage 12 such that cage 12 comprises a posterior fulcrum during posteriorcompression. Arms 140 a, 140 b selectively rotate vertebrae L4, L5, inthe direction shown by arrows F in FIG. 17, about cage 12 to achievesegmental lordosis of vertebrae L4, L5. In some embodiments, as shown inFIG. 17, surgical instrument 140 includes a protractor 160, similar toprotractor 60 described herein, connected via bolt 152.

In some embodiments, spinal implant system 10 as depicted generally inFIGS. 14-17, may be used in a direct lateral (DLIF) procedure. Referringgenerally to FIGS. 14 and 16, surgical instruments 40 and/or 140 may beused in pairs to tether both sides of the vertebrae as cage 12 (forexample, using two pairs of SAS 14 across a pair of vertebrae). In suchembodiments, cage 12 may comprise a large-footprint DLIF cage, such as,for example, the CLYDESDALE® spinal system available from MedtronicSpinal and Biologics. In some such cases, the DLIF cage 12 may be usedas a fulcrum about which the instruments 40 and/or 140, depending on theembodiment, may impart lordosis-inducing forces as described throughoutthe present disclosure. In DLIF embodiments, the cage 12 may be placedmore anteriorly than the cage 12 depicted generally in FIGS. 14-15. Forexample, in some DLIF cases, the patient may be placed in a lateralposition such that posterior access to the instruments 40 and/or 140 maybe available to the surgeon, along with simultaneous DLIF access for theinsertion of the cage 12. In some such DLIF cases, the cage 12 may beplaced in an anterior half of the disc space between vertebrae and thepairs of instruments 40 and/or 140 may be used to impart bilaterallordosis-inducing forces across the fulcrum established by the cage 12.

In one embodiment, as shown in FIGS. 18 and 19, spinal implant system10, similar to the systems and methods described herein, comprises asurgical instrument, such as, for example, a distractor 170. Distractor170 is utilized for transverse disc dissection and preparation across aposterior portion of a vertebral space, as described herein. Distractor170 includes an arm 172 and a transverse arm 174. Arm 174 is disposed atan angle α, as shown in FIG. 18, relative to arm 172. In someembodiments, angle α is disposed in a range 0 through 180 degrees. Insome embodiments, angle α is 90 degrees.

Arm 172 includes a handle 176 configured to facilitate manipulation ofdistractor 170. In some embodiments, arm 172 includes markings 178configured to indicate a depth of distractor 170 within a vertebralspace to prevent insertion of distractor 170 in a spinal canal and/orprevent insertion outside the annulus pulpous of vertebral space S.

In some embodiments, arm 174 includes a cutting end 180. Cutting end 180includes a cupped portion 182 and a ring curette 184. Cutting end 180 isdisposed at an angle β as shown in FIG. 19, relative to arm 174 andrelative to an axis disposed transverse to arm 172. In some embodiments,angle β is disposed in a range 0 through 180 degrees. In someembodiments, angle β is 30 degrees. Curette 184 is configured as aright-angled down-biting ring to facilitate safe disc removaltransversely across a posterior portion of a vertebral space, asdescribed herein. In some embodiments, cutting end 180 is configured tofacilitate ventrally pushing tissue within a vertebral space into ananterior portion of the vertebral space for safe removal of the tissue.In some embodiments, cutting end 180 separates cartilaginous endplatematerial and the separated fragments are pushed anteriorly into a centerportion of the vertebral space. The fragments are removed by ronguers(not shown).

In one embodiment, as shown in FIGS. 20-22, spinal implant system 10,similar to the systems and methods described herein, comprises a cage212, similar to cage 12, described herein. Cage 212 defines an axis X1.Cage 212 includes a body 214 that extends between an anterior orientedsurface 216 and a posterior oriented surface 218. In some embodiments,upon disposal of cage 212 with vertebrae V, anterior surface 216 isoriented to face an anterior side of a body, such as, for example, ananterior portion A of vertebral space S of vertebrae V. In someembodiments, upon disposal of cage 212 with vertebrae V, posteriorsurface 218 is oriented to face a posterior side of the body and bedisposed adjacent a posterior portion of vertebrae, such as, forexample, a posterior portion P of vertebral space S of vertebrae V. Insome embodiments, cage 212 is configured as a stabilizing implant thatprovides a fixed fulcrum for restoring lordosis and height to selectedvertebrae V. Cage 212 is configured to rotate about axis X1 for disposaltransversely within vertebral space S, as described herein.

Body 214 extends between an end 220 and an end 222 and defines a lengthL and a height H. Length L is configured to span between a lateralmargin of a pedicle P2 and a lateral margin of an oppositely disposedpedicle P3. In some embodiments, height H is less than length L. In someembodiments, height H is 8 to 10 mm. Height H of cage 212 facilitatesdisc height restoration at posterior portion P of vertebral space Sbetween vertebrae L4, L5.

End 220 includes an extension 226 that defines a vertebral engagingsurface 228 and a vertebral engaging surface 230. Surfaces 228, 230 areeach configured to engage tissue of a vertebral body. In someembodiments, surface 228 and/or surface 230 may be rough, textured,porous, semi-porous, dimpled, knurled, toothed, grooved and/or polishedto facilitate engagement with tissue. In some embodiments, the vertebraltissue may include intervertebral tissue, endplate surfaces and/orcortical bone.

End 222 includes an extension 232 that defines a vertebral engagingsurface 234 and a vertebral engaging surface 236. Surfaces 234, 236 areeach configured to engage tissue of a vertebral body. In someembodiments, surface 234 and/or surface 236 may be rough, textured,porous, semi-porous, dimpled, knurled, toothed, grooved and/or polishedto facilitate engagement with tissue. In some embodiments, the vertebraltissue may include intervertebral tissue, endplate surfaces and/orcortical bone.

In some embodiments, cage 212 is configured for insertion via a TLIFprocedure, similar to that described herein. Cage 212 is inserted intovertebral space S along length L. As cage 212 enters vertebral space S,cage 212 is rotated about axis X1 for disposal transversely acrossvertebral space S at posterior portion P for selective orientation ofcage 212 with vertebrae L4, L5 to align cage 212 with posterior portionP of the vertebral endplates having a higher strength and resistance tosubsidence. Cage 212 is disposed such that end 220 is disposed adjacentpedicle P3 and end 222 is disposed adjacent pedicle P2. Surfaces 228,234 engage an endplate surface of vertebra L4. Surfaces 230, 236 engagean endplate surface of vertebra L5. Cage 212 comprises a posteriorfulcrum during posterior compression upon manipulation of vertebrae L4,L5 to selectively rotate vertebrae L4, L5 about cage 212 to achievesegmental lordosis of vertebrae L4, L5, as described herein. In someembodiments, bone graft and/or other biologics can be insertedanteriorly into vertebral space S prior to insertion of cage 212.

In one embodiment, as shown in FIGS. 23-28, spinal implant system 10,similar to the systems and methods described herein, comprises aninterbody implant 312, similar to the spinal implants described herein.Interbody implant 312 defines an axis X2. Interbody implant 312 includesa body 314 having surfaces 316, 318, 320 and 322. In some embodiments,surfaces 316, 318, 320 and 322 form an I-beam configuration. Interbodyimplant 312 is configured as a stabilizing implant that provides a fixedfulcrum for restoring lordosis and height to selected vertebrae L4, L5,as shown in FIGS. 27 and 28. In some embodiments, interbody implant 312is configured to rotate about axis X2 for disposal transversely withinthe disc space, as described herein.

Body 314 extends between an end 324 and an end 326. Body 314 defines alength L1 and a height H1. Length L1 is configured to span across alateral margin of a pedicle and a lateral margin of an oppositelydisposed pedicle adjacent posterior portion P. Body 314 includes aheight H2. In some embodiments, height H1 and height H2 are less thanlength L1. Rotation between height H1 and height H2 facilitates discheight restoration at posterior portion P.

Upon rotation of interbody implant 312, as described herein, surfaces316, 318 define vertebral engaging surfaces. Surfaces 316, 318 are eachconfigured to engage tissue of the endplate surface of vertebrae L4, L5.In some embodiments, surface 316 and/or surface 318 may be rough,textured, porous, semi-porous, dimpled, knurled, toothed, grooved and/orpolished to facilitate engagement with tissue. In some embodiments, thevertebral tissue may include intervertebral tissue, endplate surfacesand/or cortical bone.

In some embodiments, interbody implant 312 is configured for insertionvia a TLIF procedure, similar to that described herein. A surgicalinstrument, such as, for example, an inserter 400 is utilized to insertinterbody implant 312 and rotate interbody implant 312, as describedherein. Inserter 400 is a dynamic insertion instrument such thatinserter 400 enables insertion of interbody implant 312 into vertebralspace S in a selected configuration, such as, for example, along alinear pathway, straight ahead orientation and/or rotation. Afterinsertion and/or disposal of interbody implant 312 at a surgical site,inserter 400 is configured to initially rotate and angle interbodyimplant 312, as shown by arrow R1 in FIGS. 25 and 27, transverselybetween the pedicles. Inserter 400 is configured to achieve a secondrotation to rotate interbody implant 312 about axis X2, as shown byarrow R2 in FIG. 28, between height H1 and height H2 for engagement withendplate surfaces E1, E2 and to facilitate reduction of thespondylolisthesis.

Inserter 400 extends between and end 402 and an end 404. End 402includes an actuator 406 configured to actuate insertion and rotation ofinterbody implant 312. End 404 is configured for releasable attachmentwith interbody implant 312. Inserter 400 includes a planetary gear-train410 configured to provide an increased mechanical advantage andfacilitate orientation and alignment of interbody implant 312 duringinsertion, first rotation R1 and second rotation R2. In someembodiments, planetary gear train 410 is a mechanism for transmittingrotational motion by spur or bevel gears that include planet gears orpinions that undergo compound motion and have a moving axis of rotation.In some embodiments, a carrier supports the axles of the planet gears.In some embodiments, the planet gears mesh with a central gear thatrotate about the shaft of the mechanism.

Interbody implant 312 is inserted into vertebral space S along length Lsuch that surface 320 engages vertebra L4 and surface 322 engagesvertebra L5. As shown in FIG. 22, as interbody implant 312 entersvertebral space S, inserter 400 is actuated to rotate interbody implant312, as shown by arrow R1 in FIGS. 25 and 27, for orientation ofinterbody implant 312 transversely across vertebral space S at posteriorportion P between pedicles, as described herein. Interbody implant 312is rotated for disposal with vertebrae L4, L5 to align interbody implant212 with posterior portion P and the vertebral endplate surfaces havinga higher strength and resistance to subsidence. Inserter 400 is actuatedfor rotation R2 of interbody implant 312, as shown in FIG. 28, such thatsurface 316 rotates into engagement with endplate surface E1 of vertebraL4 and surface 318 rotates into engagement with endplate surface E2 ofvertebra L5, such that surfaces E1, E2 exert a compressive force oninterbody implant 312. Rotation R2 increases the height of cage 312 fromheight H1 to height H2 such that interbody implant 312 comprises afulcrum for rotation of vertebrae L4, L5 about interbody implant 312 tofacilitate creating segmental lordosis. In some embodiments, cage 312comprises a posterior fulcrum during posterior compression uponmanipulation of vertebrae L4, L5 to selectively rotate vertebrae L4, L5about cage 312 to achieve segmental lordosis of vertebrae L4, L5, asdescribed herein. In some embodiments, bone graft and/or other biologicscan be inserted anteriorly into vertebral space S prior to insertion ofcage 312.

In one embodiment, as shown in FIGS. 29-31, spinal implant system 10,similar to the systems and methods described herein, comprises a cage512, similar to the spinal implants described herein. Cage 512 includesa member 514 and a member 516. Cage 512 defines an axis X5 and extendsbetween an end 518 and an end 520. Member 514 defines a longitudinalaxis X6 disposed substantially perpendicular to axis X5. Member 514includes a surface 522 that defines a vertebral engaging surface 524.

Member 514 includes a surface 530 that defines a tapered cavity 532 anda tapered cavity 534. Cavities 532, 534 are configured for moveabledisposal of an actuator, such, as for example, a screw 536, as describedherein. Member 516 defines a longitudinal axis X7 disposed substantiallyperpendicular to axis X5 and parallel to axis X6. Member 516 includes asurface 540 that defines a vertebral engaging surface 542.

Member 516 includes a surface 548 that defines a tapered cavity 550 incommunication with cavity 532 to form an opening 552. Member 516includes a tapered cavity 554 in communication with cavity 534 to forman opening 556. Opening 552 includes a stop 558 configured to limitrelative movement of members 514, 516. Openings 552, 556 are incommunication at a stop 560 configured to limit relative movement ofmembers 514, 516. Openings 552, 556 are configured for disposal of screw536, as described herein. Members 514, 516 are configured for relativetranslation upon actuation of screw 536.

Screw 536 is configured for disposal with openings 552, 556. Screw 536includes a wedge 570 and a wedge 572. Wedges 570, 572 each include aninner threaded surface that defines a cavity for disposal of screw 536.As screw 536 is rotated, screw 536 rotates in engagement with wedges570, 572 such that wedges 570, 572 are translated relative to screw 536causing wedges 570, 572 to translate laterally and expand members 514,516. Wedges 570, 572 translate along screw 536 causing members 514, 516to expand and increase in height along axis X5 for engagement withvertebrae L4, L5 forming a posterior fulcrum during posteriorcompression to selectively rotate vertebrae L4, L5 about cage 512 toachieve segmental lordosis of vertebrae L4, L5, as described herein.

Screw 536 extends parallel to axes X6, X7. Screw 536 is configured torotate within openings 552, 556 to facilitate expansion and contractionof members 514, 516 via wedges 570, 572. Rotation of screw 536 causesaxial translation of wedges 570, 572 such that wedges 570, 572 aremovable relative to members 514, 516 along the tapered cavities 532,550, 534, 554 of openings 552, 556 to expand and collapse cage 512 toincrease and/or decrease lordosis about cage 512.

An instrument 600 is connected with cage 512 to facilitate insertion ofcage 512 and rotation of cage 512 for positioning transversely betweenpedicles. Cage 512 is inserted into a vertebral space (not shown) suchthat surface 524 engages an endplate surface of a vertebra and surface542 engages an endplate surface of an adjacent vertebra. As cage 512enters the vertebral space, instrument 600 is actuated to dispose cage512 transversely across a posterior portion of the vertebral space,similar to that described herein, for selective orientation of cage 512with vertebrae to align cage 512 with the posterior portion of vertebralendplate surfaces having a higher strength and resistance to subsidence.

Instrument 600 is configured to actuate screw 536 to cause expansionand/or contraction of cage 512 at the posterior portion forming aposterior fulcrum during posterior compression to selectively rotate thevertebrae about cage 512 to achieve segmental lordosis of the vertebrae,as described herein.

In one embodiment, as shown in FIG. 32, spinal implant system 10,similar to the systems and methods described herein, comprises a cage612, similar to the spinal implants described herein. Cage 612 includesa cloverleaf configuration having a central portion 614 with extensions616. Cage 612 loads endplate surfaces adjacent a posterior portion ofvertebrae adjacent to pedicles, similar to that described herein, todecrease the risk of subsidence into tissue.

In one embodiment, as shown in FIG. 33, spinal implant system 10,similar to the systems and methods described herein, comprises a cage712, similar to the spinal implants described herein. Cage 712 includesan oval configuration and loads endplate surfaces adjacent a posteriorportion of vertebrae adjacent to pedicles, similar to that describedherein, to decrease the risk of subsidence into tissue.

In one embodiment, as shown in FIG. 34, spinal implant system 10,similar to the systems and methods described herein, comprises a cage812, similar to the spinal implants described herein. Cage 812 includesan arcuate configuration and loads endplate surfaces adjacent aposterior portion of vertebrae adjacent to pedicles, similar to thatdescribed herein, to decrease the risk of subsidence into tissue.

It will be understood that various modifications may be made to theembodiments disclosed herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplification of thevarious embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

What is claimed is:
 1. A method for treating a spine, the methodcomprising the steps of: disposing an interbody implant adjacent aposterior portion of an intervertebral disc space; connecting a surgicalinstrument with at least one fixation element fastened with tissueadjacent the posterior portion; and manipulating the surgical instrumentsuch that tissue adjacent the posterior portion engages the interbodyimplant and one or more vertebra rotate about the interbody implant. 2.A method as recited in claim 1, further comprising a step of deliveringthe interbody implant adjacent the posterior portion along a TLIFapproach.
 3. A method as recited in claim 1, wherein the step ofmanipulating includes rotating vertebrae adjacent the intervertebraldisc space to achieve segmental lordosis of the vertebrae.
 4. A methodas recited in claim 1, wherein the step of disposing includes placingthe interbody implant in the intervertebral disc space from a posterioraccess and the step of manipulating includes rotating the interbodyimplant to a position transverse from pedicles along a posterior,one-third of a vertebral endplate.
 5. A method as recited in claim 4,wherein the interbody implant contacts a portion of the vertebralendplate that is resistant to subsidence and forms a fulcrum forachieving segmental lordosis.
 6. A method as recited in claim 1, furthercomprising a step of rotating the interbody implant in an axial plane.7. A method as recited in claim 6, wherein the step of rotating theinterbody implant in the axial plane draws an inferior end platedorsally.
 8. A method as recited in claim 6, the step of rotating theinterbody implant in the axial plane decompresses a foramen.
 9. A methodas recited in claim 1, wherein the step of manipulating includesrotating vertebrae adjacent the intervertebral disc space to achievesegmental lordosis of the vertebrae and further comprising the step ofmeasuring the lordosis intra-operatively.
 10. A surgical systemcomprising: a spinal implant comprising a body including a firstvertebral engaging surface and a second vertebral engaging surface beingdisposable adjacent a posterior portion of an intervertebral disc space;bone graft disposable with the intervertebral disc space; and a surgicalinstrument to compress tissue with the interbody implant such that oneor more vertebra rotate about the interbody implant.
 11. A surgicalsystem as recited in claim 10, wherein the surgical instrument includesan interbody cage positioner and rotator.
 12. A surgical system asrecited in claim 10, wherein the surgical instrument comprises a leverand the spinal implant comprises a fulcrum.
 13. A surgical system asrecited in claim 10, wherein the surgical instrument includes extendersconnected with a posterior tether.
 14. A surgical system as recited inclaim 10, wherein the surgical instrument includes a lordosis gauge. 15.A surgical system as recited in claim 10, wherein the surgicalinstrument includes a cork screw tether.
 16. A surgical system asrecited in claim 14, wherein the cork screw tether includes extendersand a movable wedge disposed therebetween.
 17. A surgical system asrecited in claim 10, wherein the spinal implant includes a clover-leafconfiguration that engages tissue adjacent the posterior portion.
 18. Asurgical system as recited in claim 10, wherein the spinal implantincludes a dumbbell configuration that is inserted adjacent theposterior portion in a vertical access direction with a TLIF approach.19. A surgical system as recited in claim 10, wherein the spinal implantincludes a posteriorly expanding cage.
 20. A method for treating aspine, the method comprising the steps of: delivering an interbodyimplant adjacent a posterior portion of an intervertebral disc spacealong a unilateral TLIF approach; connecting a surgical instrument withpedicle screws fastened with tissue adjacent the posterior portion;manipulating the surgical instrument such that tissue adjacent theposterior portion exerts a compressive force on the interbody implantsuch that the interbody implant comprises a posterior fulcrum; androtating vertebrae adjacent the intervertebral disc space to achievesegmental lordosis of the vertebrae.